WSU professor says studies historically focus only on males
By Sue Vorenberg
Published: April 12, 2014, 5:00pm
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Rebecca Craft, a researcher at Washington State University, noticed a somewhat disturbing trend when she started her career as a scientist.
She found there was a significant lack of studies on how drugs affect females differently than males.
And there’s a reason for that, but it doesn’t make the study of females any less important, said Craft, who is also chairwoman of the psychology department.
The reason is that the biology of male animals is less complex than females, so doing a study on male animals is easier — and a preference for male animals has been taught in colleges for generations, she said.
“Almost all the animal research is done in males,” Craft said. “That’s been done historically because during the female cycle, hormones change and that complicates things. But that doesn’t make it any less important to study. And (the study of THC on different genders is) important in pain research because in the variety of pain disorders, they’re much more common in women than in men.”
Women tend to get migraines and other pain disorders such as irritable bowel syndrome more frequently than men do, she said.
Craft is interested in how opioids such as codeine and cannabinoids such as THC, the psychoactive compound in marijuana, create different reactions in the sexes.
In her work, she exposes the animals to the drugs and studies their reactions to the environment along with their blood, brains and other biology through the course of their hormonal cycle.
And she’s found that females often do react differently, depending on where they are in that cycle.
She recently found evidence that THC gets amplified when females ovulate. The extra estrogen at that time appears to interact with the THC, making the reaction to the drug stronger, she said.
“Female rats metabolize things a little differently than humans do,” she said. “But I think humans may have a similar reaction. What happens seems to be that the (estrogen) increases the receptors that THC binds to in the brain.”
The useful components of marijuana go far beyond the THC for pain. Another part of it, called cannabidiol, actually appears to counteract some of the anxiety and other negative effects that can occur with THC, Craft said.
And the amount of cannabidiol in marijuana may also play an important role in pain relief, she said.
“One of the most common responses (to cannabidiol) was that it decreases anxiety,” Craft said. “Anxiety can build up a person’s pain response, and if it decreases that, it may also help with pain. It also helps some people sleep.”
The ratio of cannabidiol and THC is something people may want to keep in mind as marijuana retail sales move forward in Washington, she said.
“THC and cannabidiol ratios are much different than they used to be,” Craft said. “In the 1960s, maybe a plant was 10 percent THC. Plants today, some are 24 percent THC. And at the same time, cannabidiol ratios have dropped.”
That means underground drugmakers have increased the euphoric effects of the drug, but may have also increased the amount of anxiety it causes by reducing the cannabidiol.
And that’s just one of many aspects of the plant that could use further study, Craft said.
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